I hope this question doesn't conflict with the ''don't ask questions that are too general'' in the guidelines, but I have a question that I think goes under analytical philosophy, if I am not wrong, that I can't seem to find anywhere on the internet. The question is: what does it mean to understand? It seems like there are so many other questions that hinges on this question; so many other question that will become more intelligible if this question is answered. For example, if I am wondering whether or not we will be able to understand everything there is to understand in the universe, i.e. that nothing will remain mysterious in the end, it all depends on what is meant by understanding. It can't be the same as predicting, because one may be able to predict something without necessarilty understanding it. It can't be the same as saying some words, because one may recite something someone else have said without understanding. It can't be having the correct ''images'' showing up in your mind, because the images different people use to represent the same knowledge could probably be different. I could give more of such common-sense suggestions that seem to be wrong, but I seem to end up thinking that the only possibility to explain understanding is that it doesn't exist ''in it self'' in any form (any brain state or constellation of states), but that its closest stigmatized relative, ''convincing'' is the only real part of it, and that it masks itself as understanding. Convincing is easier to operationalize, such as ''a person's grouping concepts in a certain way and attaching a relatively higher emotional commitment to it than other things'' or that ''a person is more prone to actively defend x''. But I still haven't given up hope on the semantics of understanding, and I am hoping you can give some sort of answer.